Eusebius, Onomasticon 46:21-25 (ca. 295 A.D.); Jerome 47:18-22 (ca. 390 A.D.)
Beth-horon (Jos 10:10) where Joshua chased the kings (of the Amorites). It fell into the lot of the sons of Joseph, that is, of Ephraim. And there are two villages at about the 12th milestone from Jerusalem on the way to Nicopolis (Emmaus), one of which because of its location is called Upper Beth-horon, and it was built by Solomon, and the other Lower Beth-horon, a settlement set apart for the Levites.

BIBLICAL BACKGROUND

Josh 10:10-11 The war of Joshuah against the five kingsAnd the Lord threw them into a panic before Israel, who inflicted a great slaughter on them at Gibeon, chased them by the way of the ascent of Beth-horon, and struck them down as far as Azekah and Makkedah.
As they fled before Israel, while they were going down the slope of Beth-horon, the Lord threw down huge stones from heaven on them as far as Azekah, and they died; there were more who died because of the hailstones than the Israelites killed with the sword.

Josh 16:1-7 The territory of the tribe of EfraimThe allotment of the Josephites went from the Jordan by Jericho, east of the waters of Jericho, into the wilderness, going up from Jericho into the hill country to Bethel; then going from Bethel to Luz, it passes along to Ataroth, the territory of the Archites; then it goes down westward to the territory of the Japhletites, as far as the territory of Lower Beth-horon, then to Gezer, and it ends at the sea.
The Josephites - Manasseh and Ephraim - received their inheritance.
The territory of the Ephraimites by their families was as follows: the boundary of their inheritance on the east was Ataroth-addar as far as Upper Beth-horon, and the boundary goes from there to the sea; on the north is Michmethath; then on the east the boundary makes a turn toward Taanath-shiloh, and passes along beyond it on the east to Janoah, then it goes down from Janoah to Ataroth and to Naarah, and touches Jericho, ending at the Jordan.

2Chr 8:5-6 Solomon builds Beth-horonHe [Solomon] also built Upper Beth-horon and Lower Beth-horon, fortified cities, with walls, gates, and bars, and Baalath, as well as all Solomon's storage towns, and all the towns for his chariots, the towns for his cavalry, and whatever Solomon desired to build, in Jerusalem, in Lebanon, and in all the land of his dominion.

1Macc 3:15-24 The first successes of Judas MaccabaeusOnce again a strong army of godless men went up with him to help him, to take vengeance on the Israelites. 16 When he approached the ascent of Beth-horon, Judas went out to meet him with a small company. 17 But when they saw the army coming to meet them, they said to Judas, "How can we, few as we are, fight against so great and so strong a multitude? And we are faint, for we have eaten nothing today." 18 Judas replied, "It is easy for many to be hemmed in by few, for in the sight of Heaven there is no difference between saving by many or by few. 19 It is not on the size of the army that victory in battle depends, but strength comes from Heaven. 20 They come against us in great insolence and lawlessness to destroy us and our wives and our children, and to despoil us; 21 but we fight for our lives and our laws. 22 He himself will crush them before us; as for you, do not be afraid of them."
23 When he finished speaking, he rushed suddenly against Seron and his army, and they were crushed before him. 24 They pursued them down the descent of Beth-horon to the plain; eight hundred of them fell, and the rest fled into the land of the Philistines.

MORE ANCIENT SOURCES

Josephus, War 2,516 (1st cent. A.D.)Yet did he (Gallus) destroy fifty of those that showed themselves, and burnt the city, and so marched forwards; and ascending by Bethoron, he pitched his camp at a certain place called Gabao, fifty furlongs distant from Jerusalem.

Hieronymus, Ep.108 (Peregrinatio Paulae) 8 (385 A.D.)Then, turning back along the way she had come, she reached Nicopolis. From this she passed on and climbed to Lower and Upper Beth-horon, cities which were founded by Solomon (2Chr 8:5), but later destroyed in the disasters of war.